Device and method for determining the color value of a light
First Claim
1. An apparatus for determining the color value of light emitted from a light source comprising:
- a linear graded interference filter having only one expansion direction receiving said light, said light passing through said linear graded interference filter;
a plurality of PIN photodiodes receiving light passed through said linear graded interference filter, said plurality of PIN photodiodes being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of PIN photodiodes outputting a measured signal for computing the color value of the light;
focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; and
a plurality of optical fibers which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter.
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Accused Products
Abstract
A device for determining the color value of light includes a linear graded interference filter, which has only one expansion direction through which the light is incident on a number of photodetectors. The photodetectors are arranged adjacent to one another in the expansion direction of the graded interference filter and are used to supply measuring signals, on the basis of which the color value is calculated. Focusing optics arranged in front of the graded interference filter are used to focus the light onto the photodetectors. The light is fed via a plurality of optical guides, whose light exit ends are arranged closely adjacent to one another along one or more rows extending in the expansion direction of the graded interference filter. The focusing optics contain a cylindrical lens extending in the expansion direction. Advantageously, the photodetectors are PIN photodiodes and the optical waveguides are optical fibers. The number of detectors and their position along the expansion direction determine the accuracy of the polygonal approximation of the chromaticity diagram for natural colors, and thus providing more accurate color determination.
96 Citations
19 Claims
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1. An apparatus for determining the color value of light emitted from a light source comprising:
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a linear graded interference filter having only one expansion direction receiving said light, said light passing through said linear graded interference filter; a plurality of PIN photodiodes receiving light passed through said linear graded interference filter, said plurality of PIN photodiodes being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of PIN photodiodes outputting a measured signal for computing the color value of the light; focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; and a plurality of optical fibers which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter. - View Dependent Claims (2, 3)
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4. An apparatus for determining the color value of light emitted from a light source comprising:
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a linear graded interference filter having only one expansion direction receiving said light, said light passing through said linear graded interference filter; a plurality of photodetectors receiving light passed through said linear graded interference filter, said plurality of photodetectors being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of photodetectors outputting a measured signal for computing the color value of the light; focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; a plurality of optical guides which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter; and means for displacing said focussing optics and said linear graded interference filter, and said plurality of photodetectors, relative to one another in said expansion direction. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. An apparatus for determining the color value of light emitted from a light source comprising:
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a linear graded interference filter having only one expansion direction, receiving said light, said light passing through said linear graded interference filter; a plurality of photodetectors receiving light passed through said linear graded interference filter, said plurality of photodetectors being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of photodetectors outputting a measured signal for computing the color value of the light; focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; a plurality of optical guides which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter; three output amplifiers; a plurality of parallel circuits of three resistors, outputs of said parallel circuits being connected to inputs of said three output amplifiers; and a plurality of preamplifiers connecting corresponding photodetectors of said plurality of photodetectors to corresponding parallel circuits of said plurality of parallel circuits.
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12. An apparatus for determining the color value of light emitted from a light source comprising:
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a linear graded interference filter having only one expansion direction receiving said light, said light passing through said linear graded interference filter; a plurality of photodetectors receiving light passed through said linear graded interference filter, said plurality of photodetectors being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of photodetectors outputting a measured signal for computing the color value of the light; focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; and a plurality of optical guides which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter, wherein all the light input ends of said optical guides are directed onto the same point.
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13. An apparatus for determining the color value of light emitted from a light source comprising:
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a linear graded interference filter having only one expansion direction receiving said light, said light passing through said linear graded interference filter; a plurality of photodetectors receiving light passed through said linear graded interference filter, said plurality of photodetectors being arranged adjacent to one another in said expansion direction of said linear graded interference filter, said plurality of photodetectors outputting a measured signal for computing the color value of the light; focussing optics, including a cylindrical lens extending in said expansion direction, arranged in front of said linear graded interference filter; and a plurality of optical guides which deliver light from said light source to said focussing optics and having light exit ends arranged closely adjacent to one another along at least one row extending in said expansion direction of said linear graded interference filter, wherein said plurality of photodetectors comprises more than three photodetectors and said measured signal output from each photodetectors is a value for a chromaticity diagram, a connection of each of said values forming a polygonal approximation of a chromaticity diagram for all naturally occurring colors. - View Dependent Claims (14)
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15. A method for determining the color value of light comprising the steps of:
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delivering light from a light source to focussing optics; focussing light using said focussing optics; linear graded interference filtering focussed light in one expansion direction; arranging more than three light detectors adjacent to one another in said expansion direction, said more than three light detectors receiving light from said filtering step; outputting, from said more than three light detectors, measured values from which the color value is calculated; and displacing said focussing optics and said linear graded interference filter, and said plurality of photodetectors, relative to one another in said expansion direction.
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16. A method for determining the color value of light comprising the steps of:
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delivering light from a light source to focussing optics; focussing light using said focussing Optics; linear graded interference filtering focussed light in one expansion direction; arranging more than three light detectors adjacent to one another in said expansion direction, said more than three light detectors receiving light from said filtering step; outputting, from said more than three light detectors, measured values from which the color value is calculated; plotting said measured values on a chromaticity diagram; and connecting plotted measured values to form a polygonal approximation of a chromaticity diagram for naturally occurring colors.
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17. A method for determining the color value of light comprising the steps of:
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delivering light from a light source to focussing optics; focussing light using said focussing optics; linear graded interference filtering focussed light in one expansion direction; arranging more than three light detectors adjacent to one another in said expansion direction, said more than three light detectors receiving light from said filtering step, wherein said arranging step includes positioning said more than three light detectors along said expansion direction in order to form a polygonal approximation of the chromaticity diagram of natural colors; and outputting, from said more than three light detectors, measured values from which the color value is calculated. - View Dependent Claims (18)
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19. A method for determining the color value of light comprising the steps of:
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delivering light from a light source to focussing optics; focussing light using said focussing optics; linear graded interference filtering focussed light in one expansion direction; arranging more than three light detectors adjacent to one another in said expansion direction, said more than three light detectors receiving light from said filtering step; outputting, from said mote than three light detectors, measured values from which the color value is calculated; inputting a measured signal, via a preamplifier, from each light detector to a corresponding parallel circuit of three resistors; connecting, for each parallel circuit, an output of a first resistor to an input of a first output amplifier, an output of a second resistor to an input of a second output amplifier and an output of a third resistor to an input of a third output amplifier; and outputting, from said first, second and third output amplifiers, first, second and third color signals, respectively.
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Specification